Rolling Stones singer Mick Jagger has posted a video of his trademark dance moves on Twitter to show the world he is back in shape following heart valve surgery. The 75-year-old singer appeared in top form in jogging pants, joggers and a white T-shirt, dancing flamboyantly in a studio. There was no accompanying text. Jagger underwent heart valve replacement earlier this year, forcing the Stones to delay a tour of the US and Canada to allow him to receive medical treatment. He apologised to fans, saying he hated to let them down. Originally set to begin in April, the tour is now expected to start in July, according to Billboard magazine. Australian Associated Press